http://stackoverflow.com/questions/1501920/base-copy-constructor-not-called#ifndef CSHAPE_H #define CSHAPE_H #include <string> using namespace std; //有关C++的构造以及析构的经典总结(constructor,copy constructor,operator=,destructor)： /* 1）首先对于nontrivial的类(即有virtual method,vtable等),不管你写(自定义)或是没写(default) copy control,constructor,destructor,编译器都会为你添加一些代码. 2）对于copy control,constructor,destructor:若是自定义写了它们,编译器就不会生成default版本 了,但1)的代码仍旧是给你添进去的. (所以有写在private:里面这种机制) 3）constructor,destructor有栈调用默认机制;copy constructor,operator=没有，所以此两者要显式 地去调用基类的copy constructor以及operator=. */ enum color{ red, yellow, green }; int b[3]={3,2,1}; int (&p)[3]=b; class CShape{ public: //凡是有virtual函数的类,就说明它会被多态,所以它的destructor最好也是virtual的 virtual ~CShape(){} //rule of three CShape(const char* p){ this->shapeName=p; } CShape(const CShape& p){ shapeName=p.shapeName; } CShape& operator= (const CShape& p){ if(this==&p) return *this; shapeName=p.shapeName; } //virtual(not pure)是继承接口以及缺省行为 virtual void show(); //pure virtual是只继承接口 //接口继承 virtual void draw()=0; //非虚拟函数的目的是让derived class继承接口以及实现 //实现继承 void shapeShow(); void setShapeName(); //static管它是不是abstract class,照样可以使用CShape::showP函数 static void showP() { cout<<p[0]<<" "<<p[1]<<" "<<p[2]<<" "<<endl; } private: string shapeName; }; void CShape::show(){ cout<<this->shapeName<<endl; } void CShape::shapeShow() { cout<<this->shapeName<<endl; } void CShape::setShapeName(){ shapeName="hello"; } class Rectangle:public CShape{ public: virtual ~Rectangle(){} Rectangle(const char *p):CShape("SHAPE"),rectName(p){ //enum的使用 //color rectColor=red; } //显式调用基类的copy constructor,operator= Rectangle(const Rectangle& p):CShape(p){ rectName=p.rectName; } Rectangle& operator= (const Rectangle& p){ if(this==&p) return *this; CShape::operator =(p); rectName=p.rectName; } virtual void draw(); virtual void show(); //即static method不可以操作nonstatic member,只能操作static member //但是倒过来,nonstatic method可以操作static member /* static void sprint(){ cout<<"shape:"<<shapeshow(); cout<<"rect:"<<show(); } */ void print(){ cout<<"shape:"; shapeShow(); cout<<"rect:"; show(); } private: string rectName; }; void Rectangle::draw(){ cout<<"rectangle drawing"<<endl; } void Rectangle::show(){ cout<<this->rectName<<endl; } #endif // CSHAPE_H
